The brain is densely packed with many different types of cells, making it hard for researchers to isolate particular kinds of cells to see what genes they are expressing under different circumstances. That can hinder research that focuses on the activity of particular cell types, such as studies of Huntington’s disease in which striatal neurons degenerate.

To highlight the genetic translation activity of specific cell types in the central nervous system, Myriam Heiman led the invention of TRAP, or Translating Ribosomal Affinity Purification (published in Cell in 2008 and further described in Nature Protocols in 2014) while at the Rockefeller University as a post-doctoral fellow working with Paul Greengard and Nathaniel Heintz.

The technique starts by targeting cells of a specific type based on particular genetic characteristics and then attaches a fluorescent tag to the polyribosomes in the cells as they are processing messenger RNA (mRNA). A bead coated with a molecule to capture the fluorescing tags then captures only the tagged polyribosomes and the attached mRNA. This enables the technique to isolate the mRNA specifically being expressed by targeted cell types.

At the Picower Institute, Heiman employs TRAP in studies not only of Parkinson’s disease but also Huntington’s disease, in which medium-sized spiny neurons of the striatum are earliest and most dramatically affected.